Evaluation of the Bio Pump for Long-Term Cardiac Support Without Heparinization

A three-part study was designed to evaluate whether the Bio Pumpa and a heparinless regimen could prevent the complications of hemorrhage and inflow destruction in patients needing long-term cardiac support following cardiopulmonary bypass surgery. Five dogs underwent venoarterial membrane support for 24 hours using the Bio Pump with heparinization to maintain ACT’s in the range of 150–175 sec. All dogs survived with no sequelae. Five dogs received left ventricular support without oxygenation using the Bio Pump and no heparinization. These also survived 24 hours of support with no sequelae. Minimal bleeding, no inflow obstruction, slight increases in serum hemoglobin were common in both groups. Group 2 suffered less platelet depletion and aberration of clotting parameters thandid Group 1. A sheep undergoing left ventricular support for 14 days showed few effects until a thrombus, apparently thrown from the bearing housing of the Bio Pump, lodged in the right kidney causing a large infarct. Left ventricular assist using the Bio Pump and no anticoagulation has been used on six patients with survival in 50% of the cases.